1. Field of the Invention
The present invention relates to a liquid crystal display device.
2. Description of the Related Art
Conventionally, in a liquid crystal display device, between a pair of substrates having an insulating film and the like formed thereon, a sealing member for enabling injection of liquid crystal and adhering the pair of substrates to each other is formed, and the liquid crystal is injected from a liquid crystal injecting port formed in the sealing member. Specifically, the sealing member is made of a sealing material such as a thermosetting epoxy resin, and is formed by applying the sealing material on one substrate by a dispenser or the like. The substrate on which the sealing member is applied is adhered to the other substrate. After the pair of substrates are adhered to each other as described above, the liquid crystal is injected into a space surrounded by the pair of substrates and the sealing member via the liquid crystal injecting port, and the liquid crystal injecting port is shut by a liquid crystal encapsulating material.
By the way, each substrate is cut into a predetermined size after the insulating film is formed. Therefore, when a thick insulating film is provided to reach the end surface of the substrate, the cutting property is deteriorated. Further, the insulating film may be peeled, and the peeling and the like may cause intrusion of moisture from outside. Still further, when an ultraviolet (UV) curable resin is used as the liquid crystal encapsulating material, and the liquid crystal encapsulating material is irradiated with UV light to be cured after being applied to the liquid crystal injecting port, the insulating film may hinder the UV light irradiation. In order to solve such problems, there is proposed a liquid crystal display device in which the insulating film is formed up to the vicinity of the end surface of the substrate (for example, see Japanese Patent Application Laid-open No. 2003-121863).
In the liquid crystal display device described in Japanese Patent Application Laid-open No. 2003-121863, as illustrated in FIG. 19, a thick insulating film PAS2, which is formed on one of a pair of substrates SUB1 and SUB2 adhered to each other via a sealing member SL, in this case, the substrate SUB1, extends up to the vicinity of the end surface of the substrate SUB1 without reaching the end surface of the substrate SUB1.
However, there is a difference in thicknesses T1 and T2 between the substrates SUB1 and SUB2 at a liquid crystal injecting port 1 in the vicinity of the end surface of the substrate. Therefore, there occurs a difference in pressure to be applied to the sealing member SL when the substrates SUB1 and SUB2 are adhered to each other. This difference causes, as illustrated in FIG. 18, steps 2 and 2 to be generated at both ends of the sealing member SL in a width direction. As a result, the following problems occur. That is, the steps 2 and 2 become a portion at which air bubbles AIR accumulate at the time of liquid crystal sealing, which causes end surface peeling. In addition, the accumulated air bubbles AIR may enter inside a display region, which causes display failure.